A recent radio communication environment has been facing the problem of depletion of frequency resources due to a rapid increase in data traffic. Accordingly, as one of measures against the depletion of the frequency resources, a heterogeneous network has been attracting attention. The heterogeneous network is a network that is formed by allowing various cells different in a radio access technology, a cell size or a frequency band to coexist. For example, there is proposed that, for the fifth-generation (5G) radio communication system after the 3GPP Release 12, a relatively low frequency band is allocated to a macro cell and a relatively high frequency band is allocated to a small cell to allow the macro cell and the small cell to be overlapped with each other (see Non-Patent Literature 1 below). Accordingly, network density can be enhanced and use efficiency of the frequency resources can be improved.